Change-gear mechanism.



W. SCHELLENBAGH.

CHANGE GEAR MECHANISM.

APPLICATION FILED O0T.28, 1912.

2 SHEETB-SHEET 1.

Patented July 8, 1913.

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CHANGE GEAR MECHANISM.

APPLIOATION F LED 00T.28, 1912.

m N Y m Patented July 8', 1913.

l M W l W m M m m w M w K My LM/M To all whom, it may concern:

UNITED STATES PATENT OFFICE WILLIAI sonELLE'NBAcn, oF mwwnLL, 011-10.

Be it known that 1, WILLIAM SCHELLEN- neon, a citizen of the UnitedStates, residing at Hartwell, in the county of Hamilton and State ofOhio, have invented certain new and useful Improvements in Change- GearMechanism, of which the followingis a specification.

This invention relates to means for enabling a member to be fed at arate corresponding either to any one of a plurality of so-called Englishpitches, or to any one of a plurality of so-called metric pitches, andto enable the change to be efl'ected quickly and in a simple manner; butin a more concrete sense, it proposes an instrumentality forming a partof a screw cutting apparatus, as in a lathe, inwhich by the simplemovement of a system-change lever, either English "or metric threadswill. be cut and in which another lever may be moved-to enable anythread of either the English or metric systems to be out.

.Another object is to provide an arrangement such that the manufacturermay use a standard construction adapted for satisfying the demands ofcustomers wishing to cut English threads only, and to correlate withthis standard construction certain simple elements adapted to be readilyapplied to the same, to extend its capacity, whereby the apparatus mayalso cut metric threads with equal facility.

Another object is to devise a mechanism whereby either English or metricthreads may be cut, without any operation other than the simple movementof a systemchange lever, and whereby threads of various ranges can bereadily cut in either of the pitches by positioning a tumbler or pitchlever in its standard notches.

Another object is to devise a mechanism for cutting either English ormetric pitches and in which the conversion will be efi'ected in a verysimple and direct manner and in a way avoiding confusion on the part ofthe operator due to the reverse movements of designating pitches adoptedin the respec tive standards.

Other objects will be in part obvious from the annexed drawings, and inpart indicated in connection with the following description.

In order that this invention may be made more readily comprehensible tothose skilled in this art, drawings illustrating one of Specification ofLetters Patent. Application filed October 28, 1912. Serial No. 728,327

Patented July 8, 1913.

the many .possible embodiments thereof have been appended as a 'part ofthis disclosure, and in such drawings like characters of referencedenote corresponding parts throughout all the figures, of which Figure 1illustrates an 'end elevation of a lathe to which this invention hasbeen applied. Fig. 2 is a section taken through line 22 of Fig. 1,showing the details of one manner of arranging this invention. Fig.6 isa section taken through line 33 of Fig. 2, showing further details of ashifting mechanism such as may be used in connection with thisinvention.

As rendering better understood the gen eral character of this invention,it may be here noted that in the English or \Vhitworth system, the indexis based on the number of threads in a unit of length (the inch) whilein the metric system, the index is based on the size of each thread, 2'.0., the number of length units (millimeters) in each thread.Consequently, as the index of the English system increases, say alongthe series 32, 36,

. 38, 4:0, etc., the threads become progressively finer. Conversely,however, as the index of the metric system, increases, say along theseries 1mm, 1% mm., 1 1-. mm., 11 mm., the threads become progressivelycoarser. In devising an attachment to cut in either system it istherefore highly desirable to preserve the order of the index seriescustomary in each case, to prevent confusion, and in shifting themechanism from one sys tem. to the other it must therefore also operateto cut progressively finer threads in the English shift, andprogressively coarser threads in the metric shift, with an ascendingseries of index numerals in both cases. Now, in older forms ofsingle'systcm thread cutting devices, it was usual to effect thenecessary changes of relative speeds by removing one or more of thegears between the work turning spindle and the tool carrier andsubstituting others to change the gear ratio. This was done by hand andwas troublesome and easily permitted of errors. By subsequentimprovements, the gears in single-system devices were all mounted in acasing and an arrangement was made so that by merely shifting a tumblerlever from one notch or hole to another, the proper ratio automaticallywould be obtained. This was a great convenience, but as the holes ornotches indicated an ascending series applicable say to the Englishsystem, they would not apply for the converse series of the metricsystem if the customary index order is to be preserved unless apermanent rearrangement be made in the construction of the gear box. Bythis invention, however, it becomes possible in a double-system threadcutting device, to overcome these difficulties so that, by the simpleshifting of a system-change le- 13 ver, when the other tumbler lever ismoved and set at holes A, B, G, 1), etc., the device will cut Englishthreads 32, 36, 38, 40, re-

spectively, or it will cut metric threads 1 mm., 1% mm., 1, mm., or1%,=.m1n., re- 15 spectively, notwithstanding the converse status of thecustomary index of these two systems. Continuing now by way of a morecomplete disclosureof the underlying principles and features of thisinvention, it may be stated that the description, while dealing largelywith specific features is to be taken in an illustrative or explanatorysens-e, rather than in a limiting sense, inasmuch as the features of theinvention may skilled in the art in the light of this disclosure. Itwill suffice to show this mechanism in connection with certain parts ofan engine lathe without entering into a detailed description ofconventional lathe elements.

In Fig. 1, 1 indicates the head-stock end carriage adapted to slide onslide-ways provided by the bed of the lathe, and that a socalled leadscrew operates to propel such carriage. These parts being purely conven:tional, will be adequately comprehended by those skilled in the art, andhencerequire no illustration other than as indicated by Fig. 1.,Intervening between such spindle and lead screw is arranged gearing sodesigned as to insure the proper ratio of movements between the work andthe tool required for the cutting of the predetermined thread orthreads. .In the example shown, a gear 4 is keyed to the left hand endof the spindle. This gear communicates mot-ion to an intermediate gear 5carried by an arm 6 journaled on a bearing 7 so that this gear may bereadily interchanged in posit-ion by others to reverse movements, orchange the speed ratios. Thus, by swinging the arm 6,

e0 gear 25 may be brought into mesh with gear 4 (see Fig. 1), to actthrough gear 5 to reverse the motion. Or by sliding gear 8 to the left,it will mesh with gear 27 and receive motion through pinion 26 and gear25 5 to reduce the speed ratios. The gear 5 in assume different formsfrom that shown, as will be readily comprehended by those turn mesheswith a gear 8 splined to a turnbler sleeve 9, also mounted in thebearing 7 and having a clutch 10 at its right hand end. The clutch 10becomes effective when English or Whitworth-threads are to be out. m Itwill be convenient in continuing this description first to describe theparts as arranged for cutting English threads, and then explain how themetric threads are out. In cutting English threads the parts are 5positioned as shown by Fig. 2. Passing freely through the bore of thesleeve 9 is a tumbler shaft 12, which is in this case rotated directlyby the sleeve 9, and to this end it carries a clutch 13 that is broughtinto looking relation with the sleeve-clutch" 10, by translating theshaft 12 to the left. The means for shifting this shaft will bedescribed presently. Splined to this tumbler shaft is a gear 14 that isintended to be brought into mesh with any one ofa series of gears, so tovary the gear ratio that a corresponding one of a range of threads maybe out. To enable this gear 14 to be shifted longitudinally on thetumbler shaft, there is 99 provided a part 15 in which such gear isjournaled, and an arm 16 extends from such part and forms ahand-actuated member, which may be provided with a plunger stop 18cooperating with a plurality of holes or 5 notches having the purpose offixing the position of the gear 14 through the aforesaid parts. Anintermediate or tumbler gear 17 is shown, also carried on the swingingand shifting arm 16 to serve as a meansinstru- 100 mental in enablingthe gear 14 to be geared to gears'of the different diameters necessary.for obtaining the different ratios. These change-ratio gears areindicated by A to K, included, and are all keyed on the cone-gear shaft19 that is journaled at its right hand end in a fixed bearing 20. Thus,in cutting English threads, the motion is transmitted through the gearsand parts aforesaid to either of the gears A, B, C, etc.,'which in thiscase are driven directly by the intermediate gear 17 (in the metricthese gears are drivers for gear 17) and these turn shaft 19 at a ratecorrespondingtothe thread to be out.

30 on the lead screw 31. In the English shift they are driven by thecone-gear shaft 19 by being in effect clutched directly thereto, 130

Of the parts shown, the ears ,21 and 22 are those ultimately driven ineither the while in the metric shift, they are driven at a differentspeed from the shaft 19 by other means. Such gears 21 and 22 aretherefore normally freely mounted on the shaft 19, and have a clutch 24adapted to be engaged with a companion clutch member on a gear splinedto the shaft 19, so as to be enabled to be shifted out of engagementtofree the gears 21 and 22 from the shaft 19 when metric threads are to becut.

The metric thread cutting may now be described, and in explaining themeans instrumental in so doing, it Wlll be convenient to use lower casealphabetical letters in" designating parts other than those alreadydescribed.

Arranged at the left hand ends of the shafts 12 and 19. is the shiftingmechanism shown in detail by Fig. 3. This consists of a supportingcasting a having upper and lower holes. In the upper hole is contained arack-sleeve Z) that is splined therein and is loosely mounted on thetumbler shaft 12,

as by means of a bushing c.- Collars d and e restrain this rack-sleevefrom longitudinal movement with respect to the tumbler shaft 12 so thatthe latter may be shifted axially by moving the rack sleeve 7). Toenable this to be done, a shaft f is journaled in the casting a and isprovided with a gear 9 meshing with the teeth of the rack sleeve 6. Theshaft f terminates in an operatinglever h having some conventional meansfor holding it in its predetermined positions; as for example, a springplunger operatingin suit able holes or notches in the casting a. In theother hole and on the other side of the shaft f is a second rack sleeve5 also splined therein and meshing with a gear on the shaft f, as in thecase of the sleeve 6. The

sleeve 2' is revolubly journaled on the hub of a gear j that is in turnsplined to the shaft 19 and also has a bearing in the wall 23 of thecompound gear casing. A gear is also mounted on the casing a and mesheson the one hand with gear j and on the other hand with a gear Z that isloosely mounted on the tumbler shaft 12 and has a clutch m. Now, whenthe system change lever hiis turned clockwise, the tumbler shaft 12 ismoved longitudinally to the right until the clutch m engages itscompanion member on the sleeve 9 and the clutch at 10 simultaneouslybecomes discngaged. The-effect of this is that the tumbler shaft 12 isfreedvfrom direct driving engagement with the sleeve 9, and, as willpresently appear, it is driven from the cone of gears instead of beingthe driver for such coup. The gear Z, now being clutched to the sleeve9, is driven thereby (independently of shaft 12) and it turns the geark, and, through the latter, the gear 7' is rotated. The shaft 19 is thendriven in turn, but it is to be noted that the clutch 24 is nowdisengaged (by the movement to the left of the rack-sleeve i by theshaft 1) and the-gears 21 and 22 now may be moved independently of thecone-gear shaft 19 which is driven by gear j. Either of the cone ofgears A, B, G, etc.,'will now drive the tumbler gear 17 and the gear 14will be driven and, as it is keyed directly to the tumbler shaft 12, thelatter is now driven at a rate corresponding to which of the gears A, B,C, etc., are in mesh. When the tumbler shaft 12 was moved to the right,a clutch a thereon was en 'aged with a companion clutch on a ear {I thatis journaled in a stationary caring and loosely receives the end of thetumbler shaft 12 and supports the same. This gear now drives theintermediate q and the latter turns a gear 1" keyed to a, shaft 8. Thesegears are so ratioed as to provide the constant necessary to effect aconversion of the relative movements of the parts so as to satisfy therequirements of the metric system. The shaft .9 at its other end drivesthe gear at that in turn meshes with an intermediate u which meshes withand drives the gear w that is journaled in a bearing formed by a hubfrom the casing 23. The gear o is loose on the shaft 19, but it isclutched to the 1 gears 21 and 22 by means of the' tenent clutch to sothat the latter are now rotated by gear 2) independently of the shaft19, and at the rate or rates required for cutting the metric threads.When, for cutting English threads, the clutches 10 and 24 are engaged,and the clutches m and 0 are disengaged, the gears j, 71:, and l as wellas the gears v, a, t, r, qand p turn ineffectively. This train from p toc constitutes an evaluating gearing that introduces the constant orfactor in the system necessary to enable the gears C to K to be used inan order inverse to that employed for the English system, whereby themetric system is available in the way that foreigners are accustomed to.Thus, when this evaluating gearing is thrown in, thegea-r ratios aresuch that change-gears C, D, E, etc., will exactly correspond to a givenwell-known standard pitch in the metric sys: tem, thus avoidingirregular pitches. The same condition prevails also for the Englishsystem. By making this evaluating gearingan automatically availableelement of this arrangement, a greatconvenience is afforded the user,and by bringing it compactly and simply into the mechanism, the cost ofproduction is reduced and its desirability enhanced. J

I therefore claim and desire to secure by Letters Patent 1. An apparatusof the nature disclosed combining a driving member, a driven member, aseries of gears intervening between said driving and driven members, anintermediate gear, and shifting mechanism for connecting said series ofgears with said driving member independently of said inmitted in a givensequence throughsaid series of gears or through said intermediate gearin a reverse sequence through said series of gears to said drivenmember.

2. An apparatus of the nature disclosed combining two shafts, a drivinggear journaled on one shaft, a gear keyed to said other shaft, a drivenmember, a series of gears intervening between said shafts, ratioevaluating gearlng, and shifting mechanism adapted in one position toclutch thedriving gear with said shaft to connect said gear series inone order including said'evaluating gearing with said driving gear, andadapted in another position to gear said driving gear with said othershaft' to connect said gear seriesine a reverse order with said drivinggear and simultaneously to eliminate said evaluating gearing.

3. An apparatus of the nature disclosed combining a first shaft, a gearhaving a fixed movement ratio therewith, a second shaft,

speed change gearing between said gear and said second shaft, a drivinggear journaled on said first shaft, a driven gear journaled on saidsecond shaft, a'gearjournaled on said first shaft having a drivingconnection with said driven gear, clutches en said first shaft, andmeans for longitudinally translating said first shaft in one directionto clutch it with said driving gear or in an opposite direction toclutch it with said ear. g t. An apparatus of the nature disclosedcombining a first shaft, a gear having a fixed movement ratio therewith,a second shaft, speed change gearing between said gear and said secondshaft, a driving gear journale'd on said first shaft, a driven gearjournaled on said second shaft, a gear journaled on said first shaft andhaving a driving connection with said second shaft, another gear.journaled on said first shaft and having a driving connection with saiddriven gear, clutches between said d riving gear and first shaft, andbetween said first shaft and said other journaled gear, and between saiddriving gear and said first mentioned jour'naled' gear, and means forsimultaneously unclutching said first mentioned clutch andsimultaneously engaging said other clutches.

5. An apparatus of the nature disclosed combining a first shaft, a gearhaving a fixed movement ratio therewith, a second shaft, speed changegearing between said gear and said second shaft, a driving gearjournaled on said first shaft, a driven gear tending from said secondshaft to said driving gear, a clutch between said driving gear and saidgearing, a clutch between said driven gear and said second shaft,gearing ]0U1'I1{L'ld on said second shaft, gearing exextending from salddriven gear to said first shaft, a clutch between said first shaft andsaid gearing, a clutch between said driving gear and said first shaft,and means for simultaneously clutching the lasttwo mentioned clutchesand unclutching the remaining clutches, or for clutching the remainingclutches and unclutching said last two clutches.

6; An apparatus of the nature disclosed I combining a driving member, adriven member,ja series of gears intervening therebetween, ratioevaluating gearing, and means adapted in one position to connect saidgear series in one order together with said gearingwith said drivingmember, and adapted in another position to connect said gear series in areverseorder' with said driving member and toeliminate said evaluatinggearing.

In testimony whereof, I have hereunto set my hand.

WILLIAM SGHELLENBACH. Witnesses: I

, OLIVER B. KAISER,

CLARENCE B. Foe-ran.

